Merge branch 'dev' into NCBACK-33

# Conflicts:
#	src/main/java/ru/soune/nocopy/controller/ApiController.java
#	src/main/java/ru/soune/nocopy/dto/MessageCode.java
#	src/main/resources/application.yaml

src/main/java/ru/soune/nocopy/controller/ApiController.java

@@ -4,6 +4,9 @@ import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.UrlResource;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.web.PageableDefault;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
@@ -23,6 +26,7 @@ import ru.soune.nocopy.entity.file.FileStatus;
 import ru.soune.nocopy.entity.file.UploadStatus;
 import ru.soune.nocopy.exception.*;
 import ru.soune.nocopy.handler.*;
+import ru.soune.nocopy.repository.FileEntityRepository;
 import ru.soune.nocopy.service.register.AuthService;
 import ru.soune.nocopy.service.file.FileEntityService;
 import ru.soune.nocopy.service.file.FileUploadService;
@@ -34,6 +38,7 @@ import java.nio.file.Paths;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.stream.Collectors;
 
 @Slf4j
@@ -49,6 +54,10 @@ public class ApiController {
 
     private final AuthService authService;
 
+    private final FileSimilarityService fileSimilarityService;
+
+    private final FileEntityRepository fileEntityRepository;
+
     @PostMapping("/v{version}/data")
     public ResponseEntity<?> handlePostRequest(@RequestBody BaseRequest request,
                                                @PathVariable("version") int version) {
@@ -98,54 +107,63 @@ public class ApiController {
             @RequestParam(value = "chunk", required = false) MultipartFile chunk) {
         try {
             if (chunk == null || chunk.isEmpty()) {
-                return ResponseEntity.ok().body(new BaseResponse(20004, MessageCode.FILE_UPLOAD_ERROR.getCode(),
-                        "Chunk file null or empty", ChunkUploadResponse.builder()
-                        .uploadId(uploadId)
-                        .chunkNumber(chunkNumber)
-                        .build()));
+                return buildErrorResponse(uploadId, chunkNumber, "Chunk file null or empty");
             }
-
             if (uploadId == null || uploadId.isBlank()) {
-                return ResponseEntity.ok().body(new BaseResponse(20004, MessageCode.FILE_UPLOAD_ERROR.getCode(),
-                        "Upload ID is required", ChunkUploadResponse.builder()
-                        .uploadId(uploadId)
-                        .chunkNumber(chunkNumber)
-                        .build()));
+                return buildErrorResponse(uploadId, chunkNumber, "Upload ID is required");
             }
-
             if (chunkNumber == null || chunkNumber < 0) {
-                return ResponseEntity.ok().body(new BaseResponse(20004, MessageCode.FILE_UPLOAD_ERROR.getCode(),
-                        "Valid chunk number is required", ChunkUploadResponse.builder()
-                        .uploadId(uploadId)
-                        .chunkNumber(chunkNumber)
-                        .build()));
+                return buildErrorResponse(uploadId, chunkNumber, "Valid chunk number is required");
             }
 
             fileUploadService.uploadChunk(uploadId, chunkNumber, chunk);
 
-            ChunkUploadResponse responseBody = ChunkUploadResponse.builder()
-                    .uploadId(uploadId)
-                    .chunkNumber(chunkNumber)
-                    .chunkSize(chunk.getSize())
-                    .message("Chunk uploaded successfully")
-                    .build();
-
-            return ResponseEntity.ok().body(new BaseResponse(20004, MessageCode.SUCCESS.getCode(),
-                    "Chunk uploaded successfully", responseBody));
+            return buildSuccessResponse(uploadId, chunkNumber, chunk);
+        } catch (DuplicateImageException e) {
+            return ResponseEntity.ok().body(new BaseResponse(20004, MessageCode.DUPLICATE_FILE_UPLOAD.getCode(),
+                    MessageCode.DUPLICATE_FILE_UPLOAD.getDescription(),
+                    Map.of("duplicateOwnerId", e.userId(), "duplicateFileId", e.duplicateFileId())));
         } catch (Exception e) {
             log.error("Error uploading chunk", e);
-
-            ChunkUploadResponse responseBody = ChunkUploadResponse.builder()
-                    .uploadId(uploadId)
-                    .chunkNumber(chunkNumber)
-                    .build();
-
-            return ResponseEntity.ok().body(new BaseResponse(
-                    20004, MessageCode.FILE_UPLOAD_ERROR.getCode(),
-                    "Failed to upload chunk: " + e.getMessage(), responseBody));
+            return buildErrorResponse(uploadId, chunkNumber, "Failed to upload chunk: " + e.getMessage());
         }
     }
 
+    @GetMapping("/v{version}/files/{fileId}/similar")
+    public ResponseEntity<BaseResponse> findSimilarFiles(
+            @PathVariable("version") int version,
+            @PathVariable String fileId,
+            @RequestParam(required = false) List<String> similarityLevels,
+            @PageableDefault(size = 20, sort = "hammingDistance") Pageable pageable) {
+        SimilarityFilter filter = SimilarityFilter.builder()
+                .similarityLevels(similarityLevels)
+                .build();
+        Page<SimilarFileResponse> similarFiles = fileSimilarityService.findSimilarFiles(fileId, filter, pageable);
+
+        String messageDesc;
+        MessageCode success;
+
+        if (similarFiles.isEmpty()) {
+            messageDesc = MessageCode.FILE_NOT_FOUND.getDescription();
+            success = MessageCode.FILE_NOT_FOUND;
+        } else {
+            messageDesc = MessageCode.SIMILAR_FILES_FOUND.getDescription();
+            success = MessageCode.SIMILAR_FILES_FOUND;
+        }
+
+        Map<String, Object> responseData = new HashMap<>();
+        responseData.put("content", similarFiles.getContent());
+        responseData.put("page", similarFiles.getNumber());
+        responseData.put("size", similarFiles.getSize());
+        responseData.put("totalElements", similarFiles.getTotalElements());
+        responseData.put("totalPages", similarFiles.getTotalPages());
+        responseData.put("hasNext", similarFiles.hasNext());
+        responseData.put("hasPrevious", similarFiles.hasPrevious());
+
+        return ResponseEntity.ok()
+                .body(new BaseResponse(20004, success.getCode(), messageDesc, responseData));
+    }
+
     @GetMapping("/v{version}/files/progress/{uploadId}")
     public ResponseEntity<BaseResponse> getUploadProgress(
             @PathVariable("version") int version,
@@ -169,7 +187,6 @@ public class ApiController {
 
             return ResponseEntity.ok().body(new BaseResponse(
                     20004, MessageCode.SUCCESS.getCode(), MessageCode.SUCCESS.getDescription(), responseBody));
-
         } catch (Exception e) {
             log.error("Error getting progress for upload: {}", uploadId, e);
 
@@ -177,8 +194,7 @@ public class ApiController {
                     .uploadId(uploadId)
                     .build();
 
-            return ResponseEntity.ok().body(new BaseResponse(
-                    20004, MessageCode.FILE_UPLOAD_ERROR.getCode(),
+            return ResponseEntity.ok().body(new BaseResponse(20004, MessageCode.FILE_UPLOAD_ERROR.getCode(),
                     "Failed to get upload progress: " + e.getMessage(), responseBody));
         }
     }
@@ -337,6 +353,78 @@ public class ApiController {
         }
     }
 
+    private ResponseEntity<BaseResponse> checkForDuplicates(String uploadId) throws IOException {
+        Optional<FileEntity> uploadedFile = fileEntityRepository.findByUploadSessionId(uploadId);
+
+        if (uploadedFile.isEmpty() || !uploadedFile.get().getMimeType().equals("image")) {
+            return null;
+        }
+
+        FileEntity fileEntity = uploadedFile.get();
+        List<SimilarFileResponse> similarFiles = fileSimilarityService.findSimilarFiles(fileEntity.getId());
+
+        if (hasDuplicate(similarFiles)) {
+            return handleDuplicate(fileEntity, similarFiles);
+        }
+
+        return null;
+    }
+
+    private boolean hasDuplicate(List<SimilarFileResponse> similarFiles) {
+        return similarFiles.stream().anyMatch(f -> f.getHammingDistance() <= 5);
+    }
+
+    private ResponseEntity<BaseResponse> handleDuplicate(FileEntity fileEntity, List<SimilarFileResponse> similarFiles)
+            throws IOException {
+        fileEntityService.deleteFromDisk(fileEntity);
+
+        fileEntityService.markAsDeleted(fileEntity);
+
+        Optional<FileEntity> originalFile = fileEntityRepository.findById(similarFiles.get(0).getFileId());
+
+        if (originalFile.isPresent()) {
+            Map<String, String> duplicateInfo = Map.of(
+                    "duplicate_file_id", originalFile.get().getId(),
+                    "owner_user_id", String.valueOf(originalFile.get().getUserId()));
+
+            return ResponseEntity.ok().body(new BaseResponse(
+                    20004,
+                    MessageCode.DUPLICATE_FILE_UPLOAD.getCode(),
+                    "Failed to upload chunk, duplicate",
+                    duplicateInfo));
+        }
+
+        return null;
+    }
+
+    private ResponseEntity<BaseResponse> buildSuccessResponse(String uploadId, Integer chunkNumber, MultipartFile chunk) {
+        ChunkUploadResponse responseBody = ChunkUploadResponse.builder()
+                .uploadId(uploadId)
+                .chunkNumber(chunkNumber)
+                .chunkSize(chunk.getSize())
+                .message("Chunk uploaded successfully")
+                .build();
+
+        return ResponseEntity.ok().body(new BaseResponse(
+                20000,
+                MessageCode.SUCCESS.getCode(),
+                "Chunk uploaded successfully",
+                responseBody));
+    }
+
+    private ResponseEntity<BaseResponse> buildErrorResponse(String uploadId, Integer chunkNumber, String errorMessage) {
+        ChunkUploadResponse responseBody = ChunkUploadResponse.builder()
+                .uploadId(uploadId)
+                .chunkNumber(chunkNumber)
+                .build();
+
+        return ResponseEntity.ok().body(new BaseResponse(
+                20004,
+                MessageCode.FILE_UPLOAD_ERROR.getCode(),
+                errorMessage,
+                responseBody));
+    }
+
     private ResponseEntity<BaseResponse> createValidationErrorResponse(BindingResult bindingResult, Integer msgId) {
         List<Map<String, String>> fieldErrors = bindingResult.getFieldErrors()
                 .stream()

src/main/java/ru/soune/nocopy/dto/MessageCode.java

@@ -9,6 +9,7 @@ public enum MessageCode {
     TOKEN_IS_ALIVE(2, "Token is alive"),
     INVALID_ACTION(2, "Invalid action"),
     FILE_UPLOAD_ERROR(2, "File upload error"),
+    DUPLICATE_FILE_UPLOAD(2, "Duplicate file upload"),
     FILE_DOWNLOAD_ERROR(2, "File download error"),
     USER_NOT_VERIFIED(2, "User not verified"),
     USER_NOT_FOUND(2, "User not found"),
@@ -25,7 +26,8 @@ public enum MessageCode {
     AUTH_TOKEN_NOT_FOUND(4, "Token not found"),
     FILE_NOT_FOUND(4, "File not found"),
     AUTH_PASSWORD_NOT_MATCHES(2, "Password does not match"),
-    SEND_EMAIL_EXCEPTION(2, "Send email exception"),;
+    SEND_EMAIL_EXCEPTION(2, "Send email exception"),
+    SIMILAR_FILES_FOUND(0, "Similar files found");
 
     private final Integer code;
 

src/main/java/ru/soune/nocopy/dto/file/SimilarFileResponse.java

@@ -0,0 +1,14 @@
+package ru.soune.nocopy.dto.file;
+
+import lombok.Builder;
+import lombok.Value;
+
+@Value
+@Builder
+public class SimilarFileResponse {
+    String fileId;
+    String originalFileName;
+    Long fileSize;
+    Integer hammingDistance;
+    String similarityLevel;
+}

src/main/java/ru/soune/nocopy/dto/file/SimilarityFilter.java

@@ -0,0 +1,18 @@
+package ru.soune.nocopy.dto.file;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.List;
+
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public class SimilarityFilter {
+    private List<String> similarityLevels;
+    private Integer page;
+    private Integer size;
+}

src/main/java/ru/soune/nocopy/entity/file/FileEntity.java

@@ -1,5 +1,6 @@
 package ru.soune.nocopy.entity.file;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import jakarta.persistence.*;
 import lombok.*;
 import org.hibernate.annotations.GenerationTime;
@@ -65,6 +66,10 @@ public class FileEntity {
     @Column(name = "updated_at")
     private LocalDateTime updatedAt;
 
+    @OneToOne(mappedBy = "file", cascade = CascadeType.ALL, orphanRemoval = true)
+    @JsonIgnore
+    private ImageHashEntity imageHash;
+
     @PrePersist
     public void prePersist() {
         if (this.status == null) {

src/main/java/ru/soune/nocopy/entity/file/FileUploadSession.java

@@ -69,6 +69,7 @@ public class FileUploadSession {
     private String extension;
 
     @Column(name = "retry_count")
+    @Builder.Default
     private Integer retryCount = 0;
 
     @Column(name = "completed_at")
@@ -81,6 +82,7 @@ public class FileUploadSession {
     )
     @MapKeyColumn(name = "chunk_number")
     @Column(name = "chunk_path")
+    @Builder.Default
     private Map<Integer, String> chunkPaths = new HashMap<>();
 
     @PrePersist

src/main/java/ru/soune/nocopy/entity/file/ImageHashEntity.java

@@ -0,0 +1,39 @@
+package ru.soune.nocopy.entity.file;
+
+import jakarta.persistence.*;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDateTime;
+
+@Entity
+@Table(name = "image_hashes")
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+@Builder
+public class ImageHashEntity {
+
+    @Id
+    @Column(name = "file_id")
+    private String fileId;
+
+    @OneToOne(fetch = FetchType.LAZY)
+    @MapsId
+    @JoinColumn(name = "file_id")
+    private FileEntity file;
+
+    @Column(name = "hash64_hi")
+    private Integer hash64Hi;
+
+    @Column(name = "hash64_lo")
+    private Integer hash64Lo;
+
+    @Column(name = "hash_algorithm", nullable = false)
+    private String hashAlgorithm;
+
+    @Column(name = "created_at")
+    private LocalDateTime createdAt;
+}

src/main/java/ru/soune/nocopy/exception/DuplicateImageException.java

@@ -0,0 +1,20 @@
+package ru.soune.nocopy.exception;
+
+public class DuplicateImageException extends RuntimeException {
+    private final String duplicateFileId;
+    private final Long userId;
+
+    public DuplicateImageException(String message, String duplicateFileId, Long userId) {
+        super(message);
+        this.duplicateFileId = duplicateFileId;
+        this.userId = userId;
+    }
+
+    public String duplicateFileId() {
+        return duplicateFileId;
+    }
+
+    public Long userId() {
+        return userId;
+    }
+}

src/main/java/ru/soune/nocopy/handler/FileUploadHandler.java

@@ -177,40 +177,13 @@ public class FileUploadHandler implements RequestHandler {
         }
     }
 
-    private BaseResponse handleRetryUpload(BaseRequest request, FileUploadRequest fileRequest) {
-        try {
-            fileUploadService.retryFailedUpload(fileRequest.getUploadId());
-            ru.soune.nocopy.dto.file.UploadProgressResponse progress =
-                    fileUploadService.getUploadProgress(fileRequest.getUploadId());
-
-            RetryUploadResponse response = RetryUploadResponse.builder()
-                    .uploadId(progress.getUploadId())
-                    .message("Upload retry initiated")
-                    .status(progress.getStatus().toString())
-                    .build();
-
-            return new BaseResponse(request.getMsgId(), MessageCode.SUCCESS.getCode(), "Upload retry initiated",
-                    response);
-
-        } catch (UploadSessionNotFoundException e) {
-            return new BaseResponse(request.getMsgId(), MessageCode.FILE_NOT_FOUND.getCode(),
-                    "Upload session not found", null);
-        } catch (FileUploadException e) {
-            return new BaseResponse(request.getMsgId(), MessageCode.FILE_UPLOAD_ERROR.getCode(), e.getMessage(),
-                    null);
-        } catch (Exception e) {
-            log.error("Error retrying upload", e);
-            return new BaseResponse(request.getMsgId(), MessageCode.FILE_UPLOAD_ERROR.getCode(),
-                    "Failed to retry upload", null);
-        }
-    }
-
     private BaseResponse handleGetChunkStatus(BaseRequest request, FileUploadRequest fileRequest) {
         try {
             FileUploadSession session = fileUploadSessionRepository.findById(fileRequest.getUploadId())
                     .orElseThrow(() -> new UploadSessionNotFoundException(fileRequest.getUploadId()));
 
             Map<String, Boolean> chunkStatus = new HashMap<>();
+
             for (int i = 0; i < session.getTotalChunks(); i++) {
                 chunkStatus.put("chunk_" + i, session.getChunkPaths().containsKey(i));
             }
@@ -225,7 +198,6 @@ public class FileUploadHandler implements RequestHandler {
 
             return new BaseResponse(request.getMsgId(), MessageCode.SUCCESS.getCode(),
                     MessageCode.SUCCESS.getDescription(), response);
-
         } catch (UploadSessionNotFoundException e) {
             return new BaseResponse(request.getMsgId(), MessageCode.FILE_NOT_FOUND.getCode(),
                     "Upload session not found", null);

src/main/java/ru/soune/nocopy/handler/GlobalExceptionHandler.java

@@ -5,15 +5,16 @@ import org.springframework.context.support.DefaultMessageSourceResolvable;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.MethodArgumentNotValidException;
-import org.springframework.web.bind.annotation.ExceptionHandler;
-import org.springframework.web.bind.annotation.ResponseStatus;
-import org.springframework.web.bind.annotation.RestControllerAdvice;
+import org.springframework.web.bind.annotation.*;
+import ru.soune.nocopy.dto.BaseResponse;
+import ru.soune.nocopy.dto.MessageCode;
 import ru.soune.nocopy.exception.*;
 
 import java.util.Map;
 
 @RestControllerAdvice
 @AllArgsConstructor
+@ControllerAdvice
 public class GlobalExceptionHandler {
 
     @ExceptionHandler(MethodArgumentNotValidException.class)
@@ -81,4 +82,12 @@ public class GlobalExceptionHandler {
                         "message" ,ex.getMessage()
                 ));
     }
+
+    @ExceptionHandler(DuplicateImageException.class)
+    @ResponseBody
+    public ResponseEntity<BaseResponse> handleDuplicateImage(DuplicateImageException e) {
+        return ResponseEntity.ok().body(new BaseResponse(
+                20004, MessageCode.DUPLICATE_FILE_UPLOAD.getCode(),
+                "Duplicate image detected", e.getMessage()));
+    }
 }

src/main/java/ru/soune/nocopy/repository/FileEntityRepository.java

@@ -30,5 +30,8 @@ public interface FileEntityRepository extends JpaRepository<FileEntity, String>
     @Query("SELECT f FROM FileEntity f WHERE f.userId = :userId AND f.originalFileName LIKE %:keyword%")
     List<FileEntity> searchByFileName(@Param("userId") Long userId, @Param("keyword") String keyword);
 
+    @Query("SELECT f FROM FileEntity f WHERE f.status = :status")
+    List<FileEntity> searchFileEntityByStatus(@Param("status") FileStatus status);
+
     long countByUserId(Long userId);
 }

src/main/java/ru/soune/nocopy/repository/ImageHashRepository.java

@@ -0,0 +1,10 @@
+package ru.soune.nocopy.repository;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+import ru.soune.nocopy.entity.file.ImageHashEntity;
+
+@Repository
+public interface ImageHashRepository extends JpaRepository<ImageHashEntity, String> {
+    void deleteByFileId(String fileId);
+}

src/main/java/ru/soune/nocopy/repository/ImageSimilarityRepository.java

@@ -0,0 +1,54 @@
+package ru.soune.nocopy.repository;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+import org.springframework.stereotype.Repository;
+import ru.soune.nocopy.entity.file.FileEntity;
+
+import java.util.List;
+
+@Repository
+public interface ImageSimilarityRepository
+        extends JpaRepository<FileEntity, String> {
+
+    @Query(value = """
+
+            SELECT
+            f.id AS similarFileId,
+            f.original_file_name AS originalFileName,
+            f.file_size AS fileSize,
+            h.hash64_hi AS hash64Hi,
+            h.hash64_lo AS hash64Lo
+        FROM image_hashes ref
+        JOIN image_hashes h
+            ON ref.file_id <> h.file_id
+        JOIN file_entities f
+            ON f.id = h.file_id
+        WHERE ref.file_id = :fileId
+        """,
+            nativeQuery = true)
+    List<SimilarImageProjection> findCandidates(
+            @Param("fileId") String fileId
+    );
+
+    @Query(value = """
+    SELECT
+        h.hash64_hi AS hash64Hi,
+        h.hash64_lo AS hash64Lo,
+        h.file_id AS fileId,
+        f.user_id AS userId,
+        f.original_file_name AS originalFileName,
+        f.file_size AS fileSize,
+        f.stored_file_name AS similarFileId
+    FROM image_hashes h
+    JOIN file_entities f ON f.id = h.file_id
+    WHERE h.hash64_hi = :hash64Hi 
+      AND h.hash64_lo = :hash64Lo
+    """,
+            nativeQuery = true)
+    List<SimilarImageProjection> findExactDuplicates(
+            @Param("hash64Hi") Integer hash64_hi,
+            @Param("hash64Lo") Integer hash64_lo);
+}
+

src/main/java/ru/soune/nocopy/repository/SimilarImageProjection.java

@@ -0,0 +1,10 @@
+package ru.soune.nocopy.repository;
+
+public interface SimilarImageProjection {
+    Integer getHash64Hi();
+    Integer getHash64Lo();
+    String getId();
+    Long getUserId();
+    String getOriginalFileName();
+    Long getFileSize();
+}

src/main/java/ru/soune/nocopy/service/FileSimilarityService.java

@@ -0,0 +1,135 @@
+package ru.soune.nocopy.service;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageImpl;
+import org.springframework.data.domain.Pageable;
+import org.springframework.stereotype.Service;
+import ru.soune.nocopy.dto.file.SimilarFileResponse;
+import ru.soune.nocopy.dto.file.SimilarityFilter;
+import ru.soune.nocopy.repository.ImageHashRepository;
+import ru.soune.nocopy.repository.ImageSimilarityRepository;
+import ru.soune.nocopy.repository.SimilarImageProjection;
+
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.List;
+import java.util.stream.Collectors;
+
+@Service
+@RequiredArgsConstructor
+public class FileSimilarityService {
+    private final ImageSimilarityRepository repository;
+
+    private final ImageHashRepository hashRepository;
+
+    public List<SimilarFileResponse> findSimilarFiles(String fileId) {
+        var imageHashEntity = hashRepository.findById(fileId)
+                .orElseThrow(() -> new RuntimeException("Hash not found"));
+
+        Integer hash64Hi = imageHashEntity.getHash64Hi();
+        Integer hash64Lo = imageHashEntity.getHash64Lo();
+
+        List<SimilarImageProjection> candidates =
+                repository.findCandidates(fileId);
+
+        return candidates.stream()
+                .map(c -> {
+                    Integer cHi = c.getHash64Hi();
+                    Integer cLo = c.getHash64Lo();
+
+                    int hamming = hamming64(hash64Hi, hash64Lo, cHi, cLo);
+
+                    String level;
+                    if (hamming <= 5) {
+                        level = "DUPLICATE";
+                    } else if (hamming <= 12) {
+                        level = "SIMILAR";
+                    } else {
+                        level = "DIFFERENT";
+                    }
+
+                    return SimilarFileResponse.builder()
+                            .fileId(c.getId())
+                            .originalFileName(c.getOriginalFileName())
+                            .fileSize(c.getFileSize())
+                            .hammingDistance(hamming)
+                            .similarityLevel(level)
+                            .build();
+                })
+                .sorted((a, b) ->
+                        Integer.compare(a.getHammingDistance(), b.getHammingDistance()))
+                .toList();
+    }
+
+    public List<SimilarImageProjection> findDuplicatedByHash(Integer hash64Hi, Integer hash64Lo) {
+        List<SimilarImageProjection> duplicates = repository.findExactDuplicates(hash64Hi,hash64Lo);
+
+        if (duplicates.isEmpty()) {
+            return new ArrayList<>();
+        }
+
+        return duplicates;
+    }
+
+    public Page<SimilarFileResponse> findSimilarFiles(String fileId, SimilarityFilter filter, Pageable pageable) {
+        var imageHashEntity = hashRepository.findById(fileId)
+                .orElseThrow(() -> new RuntimeException("Hash not found"));
+
+        Integer hash64Hi = imageHashEntity.getHash64Hi();
+        Integer hash64Lo = imageHashEntity.getHash64Lo();
+
+        List<SimilarImageProjection> candidates = repository.findCandidates(fileId);
+
+        List<String> similarityLevels = (filter != null && filter.getSimilarityLevels() != null)
+                ? filter.getSimilarityLevels()
+                : List.of("DUPLICATE", "SIMILAR", "DIFFERENT");
+
+        List<SimilarFileResponse> allResults = candidates.stream()
+                .map(c -> createSimilarFileResponse(c, hash64Hi, hash64Lo))
+                .filter(response -> similarityLevels.contains(response.getSimilarityLevel()))
+                .sorted(Comparator.comparingInt(SimilarFileResponse::getHammingDistance))
+                .collect(Collectors.toList());
+
+        int total = allResults.size();
+        int page = (pageable != null) ? pageable.getPageNumber() : 0;
+        int size = (pageable != null) ? pageable.getPageSize() : 20;
+
+        int fromIndex = Math.min(page * size, total);
+        int toIndex = Math.min(fromIndex + size, total);
+
+        List<SimilarFileResponse> pageContent = allResults.subList(fromIndex, toIndex);
+
+        return new PageImpl<>(pageContent, pageable, total);
+    }
+
+    private SimilarFileResponse createSimilarFileResponse(SimilarImageProjection similarImageProjection,
+                                                          Integer hash64Hi, Integer hash64Lo) {
+        Integer imageProjectionHash64Hi = similarImageProjection.getHash64Hi();
+        Integer similarImageProjectionHash64Lo = similarImageProjection.getHash64Lo();
+
+        int hamming = hamming64(hash64Hi, hash64Lo, imageProjectionHash64Hi, similarImageProjectionHash64Lo);
+
+        String level;
+        if (hamming <= 5) {
+            level = "DUPLICATE";
+        } else if (hamming <= 12) {
+            level = "SIMILAR";
+        } else {
+            level = "DIFFERENT";
+        }
+
+        return SimilarFileResponse.builder()
+                .fileId(similarImageProjection.getId())
+                .originalFileName(similarImageProjection.getOriginalFileName())
+                .fileSize(similarImageProjection.getFileSize())
+                .hammingDistance(hamming)
+                .similarityLevel(level)
+                .build();
+    }
+
+    private int hamming64(int aHi, int aLo, int bHi, int bLo) {
+        return Integer.bitCount(aHi ^ bHi)
+                + Integer.bitCount(aLo ^ bLo);
+    }
+}

src/main/java/ru/soune/nocopy/service/ImageHashService.java

@@ -0,0 +1,154 @@
+package ru.soune.nocopy.service;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+import ru.soune.nocopy.entity.file.FileEntity;
+import ru.soune.nocopy.entity.file.ImageHashEntity;
+import ru.soune.nocopy.repository.ImageHashRepository;
+
+import javax.imageio.ImageIO;
+import java.awt.*;
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.LocalDateTime;
+import java.util.Arrays;
+import java.util.Map;
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class ImageHashService {
+
+    private final ImageHashRepository repository;
+
+    public Map<String, Integer> calculateHash(Path imagePath) throws IOException {
+        long hash64 = computePhash64(imagePath);
+
+        return Map.of(
+                "hi", high32(hash64),
+                "low", low32(hash64));
+    }
+
+    public void create(FileEntity file,  Map<String, Integer> stringIntegerMap) {
+        ImageHashEntity entity = ImageHashEntity.builder()
+                .file(file)
+                .hash64Hi(stringIntegerMap.get("hi"))
+                .hash64Lo(stringIntegerMap.get("low"))
+                .hashAlgorithm("PHASH64")
+                .createdAt(LocalDateTime.now())
+                .build();
+
+        repository.save(entity);
+    }
+
+    private long computePhash64(Path path) throws IOException {
+        try (InputStream is = Files.newInputStream(path)) {
+            BufferedImage image = ImageIO.read(is);
+            if (image == null) throw new IOException("Cannot read image file: " + path);
+
+            BufferedImage gray = toGrayScale(image);
+            BufferedImage resized = resizeImage(gray, 32, 32);
+
+            double[][] dct = applyDCT(resized);
+            double[][] topLeft = extractTopLeft8x8(dct);
+            double median = calculateMedian(topLeft, true);
+
+            return create64BitHashLong(topLeft, median);
+        }
+    }
+
+    private BufferedImage toGrayScale(BufferedImage image) {
+        BufferedImage gray = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_BYTE_GRAY);
+        Graphics2D g = gray.createGraphics();
+        g.drawImage(image, 0, 0, null);
+        g.dispose();
+        return gray;
+    }
+
+    private BufferedImage resizeImage(BufferedImage image, int width, int height) {
+        BufferedImage resized = new BufferedImage(width, height, BufferedImage.TYPE_BYTE_GRAY);
+        Graphics2D g = resized.createGraphics();
+        g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
+        g.drawImage(image, 0, 0, width, height, null);
+        g.dispose();
+        return resized;
+    }
+
+    private double[][] applyDCT(BufferedImage image) {
+        int w = image.getWidth();
+        int h = image.getHeight();
+        double[][] pixels = new double[h][w];
+
+        for (int y = 0; y < h; y++) {
+            for (int x = 0; x < w; x++) {
+                int gray = image.getRGB(x, y) & 0xFF;
+                pixels[y][x] = gray;
+            }
+        }
+
+        double[][] dct = new double[h][w];
+        for (int u = 0; u < h; u++) {
+            double au = u == 0 ? 1.0 / Math.sqrt(h) : Math.sqrt(2.0 / h);
+            for (int v = 0; v < w; v++) {
+                double av = v == 0 ? 1.0 / Math.sqrt(w) : Math.sqrt(2.0 / w);
+                double sum = 0.0;
+                for (int x = 0; x < h; x++) {
+                    for (int y = 0; y < w; y++) {
+                        sum += pixels[x][y] *
+                                Math.cos((2 * x + 1) * u * Math.PI / (2.0 * h)) *
+                                Math.cos((2 * y + 1) * v * Math.PI / (2.0 * w));
+                    }
+                }
+                dct[u][v] = au * av * sum;
+            }
+        }
+        return dct;
+    }
+
+    private double[][] extractTopLeft8x8(double[][] dct) {
+        double[][] block = new double[8][8];
+        for (int i = 0; i < 8; i++) System.arraycopy(dct[i], 0, block[i], 0, 8);
+        return block;
+    }
+
+    private double calculateMedian(double[][] block, boolean excludeDC) {
+        double[] vals = new double[63];
+        int idx = 0;
+        for (int i = 0; i < 8; i++) {
+            for (int j = 0; j < 8; j++) {
+                if (i == 0 && j == 0 && excludeDC) continue;
+                vals[idx++] = block[i][j];
+            }
+        }
+        Arrays.sort(vals);
+        return (vals.length % 2 == 0) ?
+                (vals[vals.length / 2 - 1] + vals[vals.length / 2]) / 2.0 :
+                vals[vals.length / 2];
+    }
+
+    private long create64BitHashLong(double[][] block, double median) {
+        long hash = 0L;
+
+        for (int i = 0; i < 8; i++) {
+            for (int j = 0; j < 8; j++) {
+                if (i == 0 && j == 0) continue;
+                hash <<= 1;
+                if (block[i][j] > median) hash |= 1;
+            }
+        }
+
+        return hash;
+    }
+
+    private int high32(long hash64) {
+        return (int) (hash64 >>> 32);
+    }
+
+    private int low32(long hash64) {
+        return (int) hash64;
+    }
+}

src/main/java/ru/soune/nocopy/service/file/FileEntityService.java

@@ -9,8 +9,12 @@ import ru.soune.nocopy.dto.file.FileResponse;
 import ru.soune.nocopy.entity.file.FileEntity;
 import ru.soune.nocopy.entity.file.FileStatus;
 import ru.soune.nocopy.entity.file.FileUploadSession;
+import ru.soune.nocopy.exception.DuplicateImageException;
 import ru.soune.nocopy.exception.FileEntityNotFoundException;
 import ru.soune.nocopy.repository.FileEntityRepository;
+import ru.soune.nocopy.repository.SimilarImageProjection;
+import ru.soune.nocopy.service.FileSimilarityService;
+import ru.soune.nocopy.service.ImageHashService;
 
 import java.io.IOException;
 import java.nio.file.Files;
@@ -18,6 +22,7 @@ import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.time.LocalDateTime;
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 @Slf4j
@@ -27,7 +32,11 @@ public class FileEntityService {
 
     private final FileEntityRepository fileEntityRepository;
 
-    @Transactional
+    private final ImageHashService imageHashService;
+
+    private final FileSimilarityService fileSimilarityService;
+
+    @Transactional(noRollbackFor = DuplicateImageException.class)
     public FileEntity createFromUploadSession(FileUploadSession session, String checksum) {
         log.info("Creating FileEntity for upload session: {}", session.getUploadId());
 
@@ -38,6 +47,21 @@ public class FileEntityService {
                 throw new IOException("File not found on disk: " + filePath);
             }
 
+            Map<String, Integer> imageHash = Map.of();
+
+            if (session.getFileType().startsWith("image")) {
+                imageHash = imageHashService.calculateHash(filePath);
+                List<SimilarImageProjection> duplicatedByHash = fileSimilarityService.findDuplicatedByHash(
+                        imageHash.get("hi"), imageHash.get("low"));
+
+                if (!duplicatedByHash.isEmpty()) {
+                    SimilarImageProjection similarImageProjection = duplicatedByHash.get(0);
+
+                    throw new DuplicateImageException("Duplicate", similarImageProjection.getFileId(),
+                            similarImageProjection.getUserId());
+                }
+            }
+
             long fileSize = Files.size(filePath);
             String originalName = session.getFileName();
             String storedName = filePath.getFileName().toString();
@@ -56,11 +80,12 @@ public class FileEntityService {
                     .build();
 
             FileEntity saved = fileEntityRepository.save(fileEntity);
-            log.info("FileEntity created successfully: {} (size: {} bytes)",
-                    saved.getId(), fileSize);
+
+            if (!imageHash.isEmpty()) {
+                imageHashService.create(saved, imageHash);
+            }
 
             return saved;
-
         } catch (IOException e) {
             log.error("Failed to create FileEntity for session {}: {}",
                     session.getUploadId(), e.getMessage(), e);
@@ -68,15 +93,6 @@ public class FileEntityService {
         }
     }
 
-
-    private String extractFileExtension(String fileName) {
-        int dotIndex = fileName.lastIndexOf('.');
-        if (dotIndex > 0 && dotIndex < fileName.length() - 1) {
-            return fileName.substring(dotIndex + 1).toLowerCase();
-        }
-        return "";
-    }
-
     @Transactional(readOnly = true)
     public FileEntityResponse getById(String fileId, int version) {
         FileEntity fileEntity = fileEntityRepository.findById(fileId)
@@ -94,39 +110,6 @@ public class FileEntityService {
         return convertToResponse(fileEntity, version);
     }
 
-    @Transactional(readOnly = true)
-    public FileEntityResponse getByFilePath(String filePath, int version) {
-        FileEntity fileEntity = fileEntityRepository.findByFilePath(filePath)
-                .orElseThrow(() -> new FileEntityNotFoundException("Path: " + filePath));
-
-        return convertToResponse(fileEntity, version);
-    }
-
-
-    @Transactional(readOnly = true)
-    public FileResponse getAllUserFiles(Long userId, int version) {
-        List<FileEntity> fileEntities = fileEntityRepository.findByUserIdAndStatus(
-                userId, FileStatus.ACTIVE);
-
-        List<FileEntityResponse> files = fileEntities.stream()
-                .map(file -> convertToResponse(file, version))
-                .collect(Collectors.toList());
-
-        long totalSize = fileEntities.stream()
-                .mapToLong(FileEntity::getFileSize)
-                .sum();
-
-        return FileResponse.builder()
-                .files(files)
-                .totalCount(files.size())
-                .totalSize(totalSize)
-                .formattedTotalSize(formatFileSize(totalSize))
-                .page(1)
-                .pageSize(files.size())
-                .build();
-    }
-
-
     @Transactional(readOnly = true)
     public FileResponse getUserFiles(Long userId, int page, int pageSize, int version) {
         List<FileEntity> allFiles = fileEntityRepository.findByUserIdAndStatus(
@@ -184,6 +167,8 @@ public class FileEntityService {
 
         Files.delete(path);
 
+        markAsDeleted(fileEntity);
+
         return true;
     }
 

src/main/java/ru/soune/nocopy/service/file/FileUploadService.java

@@ -17,7 +17,5 @@ public interface FileUploadService {
 
     void handleExpiredSession(FileUploadSession session);
 
-    public void retryFailedUpload(String uploadId);
-
     public void cancelUpload(String uploadId);
 }

src/main/java/ru/soune/nocopy/service/file/FileUploadServiceImpl.java

@@ -10,12 +10,19 @@ import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 import org.springframework.web.multipart.MultipartFile;
 import ru.soune.nocopy.dto.file.UploadProgressResponse;
+import ru.soune.nocopy.entity.file.FileEntity;
+import ru.soune.nocopy.entity.file.FileStatus;
 import ru.soune.nocopy.entity.file.FileUploadSession;
 import ru.soune.nocopy.entity.file.UploadStatus;
 import ru.soune.nocopy.exception.ChunkSizeExceededException;
+import ru.soune.nocopy.exception.DuplicateImageException;
 import ru.soune.nocopy.exception.FileUploadException;
 import ru.soune.nocopy.exception.UploadSessionNotFoundException;
+import ru.soune.nocopy.repository.FileEntityRepository;
 import ru.soune.nocopy.repository.FileUploadSessionRepository;
+import ru.soune.nocopy.repository.SimilarImageProjection;
+import ru.soune.nocopy.service.FileSimilarityService;
+import ru.soune.nocopy.service.ImageHashService;
 
 import java.io.*;
 import java.nio.file.*;
@@ -23,10 +30,7 @@ import java.nio.file.attribute.PosixFilePermission;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.time.LocalDateTime;
-import java.util.Comparator;
-import java.util.HashSet;
-import java.util.Set;
-import java.util.UUID;
+import java.util.*;
 import java.util.concurrent.CompletableFuture;
 import java.util.stream.Stream;
 
@@ -57,6 +61,15 @@ public class FileUploadServiceImpl implements FileUploadService {
 
     private Path storageRoot;
 
+    @Autowired
+    private ImageHashService imageHashService;
+
+    @Autowired
+    private FileSimilarityService fileSimilarityService;
+
+    @Autowired
+    private FileEntityRepository fileEntityRepository;
+
     @Autowired
     private FileEntityService fileEntityService;
 
@@ -129,10 +142,6 @@ public class FileUploadServiceImpl implements FileUploadService {
     @Transactional
     public UploadProgressResponse uploadChunk(String uploadId, Integer chunkNumber,
                                               MultipartFile chunkFile) {
-
-        log.info("Processing chunk {} for session {}, size: {} bytes",
-                chunkNumber, uploadId, chunkFile.getSize());
-
         FileUploadSession session = sessionRepository.findById(uploadId)
                 .orElseThrow(() -> new UploadSessionNotFoundException(uploadId));
 
@@ -173,12 +182,13 @@ public class FileUploadServiceImpl implements FileUploadService {
 
     @Async("fileUploadTaskExecutor")
     @Transactional
-    public void assembleFileAsync(FileUploadSession session) {
+    public void assembleFileAsync(FileUploadSession session) throws DuplicateImageException {
         try {
             assembleFile(session);
             log.info("File assembly completed successfully for session: {}",
                     session.getUploadId());
-
+        } catch (DuplicateImageException e) {
+            throw new DuplicateImageException("DUBL", e.duplicateFileId(), e.userId());
         } catch (Exception e) {
             log.error("Failed to assemble file for session {}: {}",
                     session.getUploadId(), e.getMessage(), e);
@@ -205,35 +215,6 @@ public class FileUploadServiceImpl implements FileUploadService {
         log.info("Upload cancelled: {}", uploadId);
     }
 
-    @Override
-    @Transactional
-    public void retryFailedUpload(String uploadId) {
-        FileUploadSession session = sessionRepository.findById(uploadId)
-                .orElseThrow(() -> new UploadSessionNotFoundException(uploadId));
-
-        if (session.getStatus() != UploadStatus.FAILED) {
-            throw new FileUploadException("Only failed uploads can be retried");
-        }
-
-        if (session.getRetryCount() >= maxRetryAttempts) {
-            throw new FileUploadException("Max retry attempts exceeded");
-        }
-
-        session.setStatus(UploadStatus.UPLOADING);
-        session.setRetryCount(session.getRetryCount() + 1);
-        session.setLastError(null);
-
-        sessionRepository.save(session);
-
-        if (session.getChunksUploaded().equals(session.getTotalChunks())) {
-            log.info("Retrying file assembly for session: {}", uploadId);
-            assembleFileAsync(session);
-        }
-
-        log.info("Upload retry initiated for session: {} (attempt {})",
-                uploadId, session.getRetryCount());
-    }
-
     @Override
     public UploadProgressResponse getUploadProgress(String uploadId) {
         FileUploadSession session = sessionRepository.findById(uploadId)
@@ -271,9 +252,42 @@ public class FileUploadServiceImpl implements FileUploadService {
         }
     }
 
-    private UploadProgressResponse processChunk(FileUploadSession session,
-                                                Integer chunkNumber,
-                                                MultipartFile chunkFile) {
+    @Async("fileUploadTaskExecutor")
+    @Transactional
+    public void completeFileProcessingAsync(FileUploadSession session) {
+        try {
+            Path filePath = Paths.get(session.getFilePath());
+            String checksum = calculateChecksum(filePath);
+
+            FileEntity fileEntity = FileEntity.builder()
+                    .userId(session.getUserId())
+                    .originalFileName(session.getFileName())
+                    .storedFileName(filePath.getFileName().toString())
+                    .filePath(session.getFilePath())
+                    .fileSize(session.getFileSize())
+                    .mimeType(session.getFileType())
+                    .fileExtension(session.getExtension())
+                    .checksum(checksum)
+                    .uploadSessionId(session.getUploadId())
+                    .status(FileStatus.ACTIVE)
+                    .build();
+
+            FileEntity saved = fileEntityRepository.save(fileEntity);
+
+            Map<String, Integer> hash = imageHashService.calculateHash(filePath);
+            imageHashService.create(saved, hash);
+
+            cleanupSessionFiles(session);
+
+            log.info("File processing completed for session: {}", session.getUploadId());
+
+        } catch (Exception e) {
+            log.error("Failed to complete file processing for session {}: {}",
+                    session.getUploadId(), e.getMessage(), e);
+        }
+    }
+
+    private UploadProgressResponse processChunk(FileUploadSession session, Integer chunkNumber, MultipartFile chunkFile) {
         String chunkPath = null;
 
         try {
@@ -291,17 +305,42 @@ public class FileUploadServiceImpl implements FileUploadService {
             log.debug("Chunk {} saved successfully. Uploaded: {}/{}",
                     chunkNumber, session.getChunksUploaded(), session.getTotalChunks());
 
-            if (session.getChunksUploaded().equals(session.getTotalChunks())) {
+            boolean isLastChunk = session.getChunksUploaded().equals(session.getTotalChunks());
+
+            if (isLastChunk) {
                 log.info("All chunks uploaded for session {}. Starting assembly...",
                         session.getUploadId());
-                sessionRepository.save(session);
-                assembleFileAsync(session);
+
+                String finalFilePath = assembleFileSynchronously(session);
+
+                if (session.getFileType().startsWith("image")) {
+                    checkForDuplicatesSynchronously(finalFilePath);
+                }
+
+                session.setStatus(UploadStatus.COMPLETED);
+                session.setFilePath(finalFilePath);
+
+                completeFileProcessingAsync(session);
+
             } else {
                 sessionRepository.save(session);
             }
 
             return UploadProgressResponse.fromSession(session);
 
+        } catch (DuplicateImageException e) {
+            if (chunkPath != null) {
+                cleanupFailedChunk(chunkPath);
+            }
+
+            log.warn("Duplicate image found for session {}: {}",
+                    session.getUploadId(), e.getMessage());
+
+            session.setStatus(UploadStatus.FAILED);
+            session.setLastError(e.getMessage());
+            sessionRepository.save(session);
+
+            throw e;
         } catch (Exception e) {
             if (chunkPath != null) {
                 cleanupFailedChunk(chunkPath);
@@ -318,6 +357,29 @@ public class FileUploadServiceImpl implements FileUploadService {
         }
     }
 
+    private String assembleFileSynchronously(FileUploadSession session) throws IOException {
+        Path finalFilePath = prepareFinalFile(session);
+
+        validateAllChunksExist(session);
+        mergeChunksToFile(session, finalFilePath);
+        validateFinalFile(session, finalFilePath);
+
+        return finalFilePath.toString();
+    }
+
+    private void checkForDuplicatesSynchronously(String filePath)
+            throws IOException {
+        Path path = Paths.get(filePath);
+        Map<String, Integer> hash = imageHashService.calculateHash(path);
+        List<SimilarImageProjection> duplicates = fileSimilarityService.findDuplicatedByHash(
+                hash.get("hi"), hash.get("low"));
+
+        if (!duplicates.isEmpty()) {
+            throw new DuplicateImageException("Duplicate", duplicates.get(0).getFileId(),
+                    duplicates.get(0).getUserId());
+        }
+    }
+
     private UploadProgressResponse handleExistingChunk(FileUploadSession session,
                                                        Integer chunkNumber,
                                                        MultipartFile chunkFile) throws IOException {
@@ -325,25 +387,24 @@ public class FileUploadServiceImpl implements FileUploadService {
         Path chunkPath = Paths.get(existingPath);
 
         if (!Files.exists(chunkPath)) {
-            log.warn("Chunk file missing, re-uploading: {}", chunkPath);
             session.getChunkPaths().remove(chunkNumber);
             session.setChunksUploaded(session.getChunksUploaded() - 1);
             sessionRepository.save(session);
+
             return processChunk(session, chunkNumber, chunkFile);
         }
 
         long existingSize = Files.size(chunkPath);
+
         if (existingSize != chunkFile.getSize()) {
-            log.warn("Chunk size mismatch, re-uploading: {} != {}",
-                    existingSize, chunkFile.getSize());
             Files.deleteIfExists(chunkPath);
             session.getChunkPaths().remove(chunkNumber);
             session.setChunksUploaded(session.getChunksUploaded() - 1);
             sessionRepository.save(session);
+
             return processChunk(session, chunkNumber, chunkFile);
         }
 
-        log.debug("Chunk {} already uploaded and valid", chunkNumber);
         return UploadProgressResponse.fromSession(session);
     }
 
@@ -402,7 +463,7 @@ public class FileUploadServiceImpl implements FileUploadService {
                 session.getUploadId(), session.getFileName());
 
         Path finalFilePath = null;
-        String checksum = null;
+        String checksum;
 
         try {
             finalFilePath = prepareFinalFile(session);
@@ -428,6 +489,8 @@ public class FileUploadServiceImpl implements FileUploadService {
                 fileEntityService.createFromUploadSession(session, checksum);
                 log.info("FileEntity successfully created for session: {}",
                         session.getUploadId());
+            } catch (DuplicateImageException e) {
+                throw new DuplicateImageException("Duplicate", e.duplicateFileId(), e.userId());
             } catch (Exception e) {
                 log.error("Failed to create FileEntity for session {} (file uploaded, but metadata not saved): {}",
                         session.getUploadId(), e.getMessage());
@@ -591,44 +654,10 @@ public class FileUploadServiceImpl implements FileUploadService {
     private void handleAssemblyFailure(FileUploadSession session, Exception e) {
         session.setStatus(UploadStatus.FAILED);
         session.setLastError(e.getMessage());
+
         sessionRepository.save(session);
-
-        log.error("File assembly failed for session {}: {}",
-                session.getUploadId(), e.getMessage());
     }
 
-
-
-//    @Override
-//    @Transactional
-//    public void cleanupExpiredSessions() {
-//        log.info("Starting cleanup of expired upload sessions");
-//
-//        LocalDateTime expiryThreshold = LocalDateTime.now().minusHours(sessionExpiryHours);
-//
-//        try {
-//            var expiredSessions = sessionRepository.findByStatusInAndCreatedAtBefore(
-//                    Set.of(UploadStatus.INITIATED, UploadStatus.UPLOADING, UploadStatus.FAILED),
-//                    expiryThreshold
-//            );
-//
-//            int cleanedCount = 0;
-//            for (FileUploadSession session : expiredSessions) {
-//                session.setStatus(UploadStatus.FAILED);
-//                session.setLastError("Session expired during cleanup");
-//                sessionRepository.save(session);
-//
-//                CompletableFuture.runAsync(() -> cleanupSessionFiles(session));
-//                cleanedCount++;
-//            }
-//
-//            log.info("Cleaned up {} expired upload sessions", cleanedCount);
-//
-//        } catch (Exception e) {
-//            log.error("Error during session cleanup", e);
-//        }
-//    }
-
     private Path getChunkDirectory(Long userId, String uploadId) {
         return storageRoot.resolve("temp")
                 .resolve("user")

src/main/java/ru/soune/nocopy/service/file/NotExistFilesCleanupService.java

@@ -0,0 +1,35 @@
+package ru.soune.nocopy.service.file;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import ru.soune.nocopy.entity.file.FileEntity;
+import ru.soune.nocopy.entity.file.FileStatus;
+import ru.soune.nocopy.repository.FileEntityRepository;
+
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.List;
+
+@Service
+@RequiredArgsConstructor
+public class NotExistFilesCleanupService {
+
+    @Autowired
+    private FileEntityRepository fileEntityRepository;
+
+    @Transactional
+    @Scheduled(fixedDelay = 30000)
+    public void cleanUpNotExistFiles() {
+        List<FileEntity> fileEntities = fileEntityRepository.searchFileEntityByStatus(FileStatus.DELETED);
+
+        for (FileEntity fileEntity : fileEntities) {
+            boolean exists = Files.exists(Paths.get(fileEntity.getFilePath()));
+            if (!exists) {
+                fileEntityRepository.delete(fileEntity);
+            }
+        }
+    }
+}